[From Nand to Tetris] 第8章 虚拟机项目 python 实现
[From Nand to Tetris] 第8章 虚拟机项目 python 实现
为防闲逛至此的看官不知所云： From Nand to Tetris 是一个在线课程，目标是指导学生从 Nand 逻辑门开始从头到尾完成一整套计算机系统。
好像撸串一样的爽快：------芯片--硬件---编译原理---操作系统---应用程序------>
这里提供的是第八章的作业，以供半路摔进坑里的同学们扶一下。。。
人家老师确实是不希望扩散答案，不过我做的过程中遇到很多坑，搞半天后发现全是些脑残原因，实在是浪费时间，希望卡壳的同学们能以增进效率为目的适当参考答案。毕竟学习这种东西，有没有学到手只有自己知道。。。
注释不多，因为代码相当 self-explanatory ，就是书上那些，没自由发挥什么。
如果你是闲逛进来，而且对这块内容有兴趣的话，强烈建议点开上面的课程链接试试，我是真心非常喜欢这门课，请收下我的安利。。。
另外还有第六章的作业答案：第6章 汇编器项目 python 实现
# _*_ coding: utf-8 _*_import sysimport osimport globclass C_TYPE: C_ARITHMETIC, C_PUSH, C_POP, C_LABEL, C_GOTO, C_IF, C_FUNCTION, C_RETURN, C_CALL = range(9)class Parser: def __init__(self, fname): self.finput = open(fname, 'rU') self.current = None self.commandPart = [] self.cType = -1 def __exit__(self, exc_type, exc_val, exc_tb): self.finput.close() def has_more_commands(self): self.current = self.finput.readline() while self.current == '\n' or self.current[:2] == '//':self.current = self.finput.readline() return self.current != '' def advance(self): self.commandPart = self.current.strip().split(' ')[:3] if self.commandPart[0] == 'add' or\ self.commandPart[0] == 'sub' or\ self.commandPart[0] == 'neg' or\ self.commandPart[0] == 'eq' or\ self.commandPart[0] == 'gt' or\ self.commandPart[0] == 'lt' or\ self.commandPart[0] == 'and' or\ self.commandPart[0] == 'or' or\ self.commandPart[0] == 'not':self.cType = C_TYPE.C_ARITHMETIC elif self.commandPart[0] == 'push':self.cType = C_TYPE.C_PUSH elif self.commandPart[0] == 'pop':self.cType = C_TYPE.C_POP elif self.commandPart[0] == 'label':self.cType = C_TYPE.C_LABEL elif self.commandPart[0] == 'goto':self.cType = C_TYPE.C_GOTO elif self.commandPart[0] == 'if-goto':self.cType = C_TYPE.C_IF elif self.commandPart[0] == 'function':self.cType = C_TYPE.C_FUNCTION elif self.commandPart[0] == 'call':self.cType = C_TYPE.C_CALL elif self.commandPart[0] == 'return':self.cType = C_TYPE.C_RETURN def command_type(self): return self.cType def arg1(self): if self.command_type() == C_TYPE.C_ARITHMETIC:return self.commandPart[0] return self.commandPart[1] def arg2(self): return self.commandPart[2]class CodeWriter: def __init__(self, fname): self.foutput = open(fname, 'w') self.uniqueFlag = 0 # 用于构造唯一的标签，每次使用后加1 self.currentFile = '' # 当前处理的文件的名字 self.currentFunc = '' # 当前处理的函数的名字 def set_file_name(self, fname): self.currentFile = fname def write_arithmetic(self, command): if command == 'add':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nM=M+D\n@SP\nM=M+1\n') elif command == 'sub':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nM=M-D\n@SP\nM=M+1\n') elif command == 'neg':self.foutput.write('@SP\nM=M-1\nA=M\nM=-M\n@SP\nM=M+1\n') elif command == 'eq':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nD=M-D\n@RET_TRUE'+str(self.uniqueFlag)+'\n' 'D;JEQ\nD=0\n@END'+str(self.uniqueFlag)+'\n0;JMP\n(RET_TRUE'+str(self.uniqueFlag)+')\n' 'D=-1\n(END'+str(self.uniqueFlag)+')\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')self.uniqueFlag += 1 elif command == 'gt':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nD=M-D\n@RET_TRUE'+str(self.uniqueFlag)+'\n' 'D;JGT\nD=0\n@END'+str(self.uniqueFlag)+'\n0;JMP\n(RET_TRUE'+str(self.uniqueFlag)+')\n' 'D=-1\n(END'+str(self.uniqueFlag)+')\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')self.uniqueFlag += 1 elif command == 'lt':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nD=M-D\n@RET_TRUE'+str(self.uniqueFlag)+'\n' 'D;JLT\nD=0\n@END'+str(self.uniqueFlag)+'\n0;JMP\n(RET_TRUE'+str(self.uniqueFlag)+')\n' 'D=-1\n(END'+str(self.uniqueFlag)+')\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')self.uniqueFlag += 1 elif command == 'and':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nM=M&D\n@SP\nM=M+1\n') elif command == 'or':self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@SP\nM=M-1\nA=M\nM=M|D\n@SP\nM=M+1\n') elif command == 'not':self.foutput.write('@SP\nM=M-1\nA=M\nM=!M\n@SP\nM=M+1\n') def write_push_pop(self, command, segment, index): if command == C_TYPE.C_PUSH:if segment == 'constant': self.foutput.write('@'+index+'\nD=A\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'local': self.foutput.write('@LCL\nD=M\n@'+index+'\nA=A+D\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'argument': self.foutput.write('@ARG\nD=M\n@'+index+'\nA=A+D\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'this': self.foutput.write('@THIS\nD=M\n@'+index+'\nA=A+D\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'that': self.foutput.write('@THAT\nD=M\n@'+index+'\nA=A+D\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'pointer': self.foutput.write('@'+str(int(index)+3)+'\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'temp': self.foutput.write('@'+str(int(index)+5)+'\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n')elif segment == 'static': self.foutput.write('@'+self.currentFile+'.'+index+'\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n') elif command == C_TYPE.C_POP:if segment == 'local': self.foutput.write('@LCL\nD=M\n@'+index+'\nD=A+D\n@R13\nM=D\n@SP\nM=M-1\nA=M\nD=M\n@R13\nA=M\nM=D\n')elif segment == 'argument': self.foutput.write('@ARG\nD=M\n@'+index+'\nD=A+D\n@R13\nM=D\n@SP\nM=M-1\nA=M\nD=M\n@R13\nA=M\nM=D\n')elif segment == 'this': self.foutput.write('@THIS\nD=M\n@'+index+'\nD=A+D\n@R13\nM=D\n@SP\nM=M-1\nA=M\nD=M\n@R13\nA=M\nM=D\n')elif segment == 'that': self.foutput.write('@THAT\nD=M\n@'+index+'\nD=A+D\n@R13\nM=D\n@SP\nM=M-1\nA=M\nD=M\n@R13\nA=M\nM=D\n')elif segment == 'pointer': self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@'+str(int(index)+3)+'\nM=D\n')elif segment == 'temp': self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@'+str(int(index)+5)+'\nM=D\n')elif segment == 'static': self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@'+self.currentFile+'.'+index+'\nM=D\n') def write_label(self, label): self.foutput.write('('+self.currentFunc+'$'+label+')\n') # 构造 (funcName$label) 格式的标记，网站上没提，但书里有 def write_init(self): self.foutput.write('@256\nD=A\n@SP\nM=D\n') self.write_call('Sys.init', 0) def write_goto(self, label): self.foutput.write('@'+self.currentFunc+'$'+label+'\n0;JMP\n') def write_if(self, label): self.foutput.write('@SP\nM=M-1\nA=M\nD=M\n@'+self.currentFunc+'$'+label+'\nD;JNE\n') def write_call(self, function_name, num_args): self.foutput.write('@RETURN_ADDRESS'+str(self.uniqueFlag)+'\nD=A\n@SP\nA=M\nM=D\n@SP\nM=M+1\n' '@LCL\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n' '@ARG\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n' '@THIS\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n' '@THAT\nD=M\n@SP\nA=M\nM=D\n@SP\nM=M+1\n' '@SP\nD=M\n@'+str(int(num_args)+5)+'\nD=D-A\n@ARG\nM=D\n' '@SP\nD=M\n@LCL\nM=D\n' '@'+function_name+'\n0;JMP\n' '(RETURN_ADDRESS'+str(self.uniqueFlag)+')\n') self.uniqueFlag += 1 def write_return(self): self.foutput.write('@LCL\nD=M\n@R13\nM=D\n' '@5\nA=D-A\nD=M\n@R14\nM=D\n' '@SP\nM=M-1\nA=M\nD=M\n@ARG\nA=M\nM=D\n' '@ARG\nD=M+1\n@SP\nM=D\n' '@R13\nA=M-1\nD=M\n@THAT\nM=D\n' '@R13\nA=M-1\nA=A-1\nD=M\n@THIS\nM=D\n' # 蠢萌蠢萌的减n次1，比下一句还省一条指令。。。 '@R13\nD=M\n@3\nA=D-A\nD=M\n@ARG\nM=D\n' '@R13\nD=M\n@4\nA=D-A\nD=M\n@LCL\nM=D\n' '@R14\nA=M\n0;JMP\n') def write_function(self, function_name, num_locals): self.currentFunc = function_name commandsInitLocals = '' for i in range(int(num_locals)):commandsInitLocals += '@LCL\nD=M\n@'+str(i)+'\nA=A+D\nM=0\n' self.foutput.write('('+function_name+')\n'+commandsInitLocals) def close(self): self.foutput.close()def process_vm_file(fpath): ''' 处理一个 .vm 文件 fpath: 待处理 .vm 文件的绝对路径 ''' parser = Parser(fpath) writer.set_file_name(os.path.basename(fpath.strip('.vm'))) while parser.has_more_commands(): parser.advance() if parser.command_type() == C_TYPE.C_PUSH or parser.command_type() == C_TYPE.C_POP:writer.write_push_pop(parser.command_type(), parser.arg1(), parser.arg2()) elif parser.command_type() == C_TYPE.C_ARITHMETIC:writer.write_arithmetic(parser.arg1()) elif parser.command_type() == C_TYPE.C_LABEL:writer.write_label(parser.arg1()) elif parser.command_type() == C_TYPE.C_GOTO:writer.write_goto(parser.arg1()) elif parser.command_type() == C_TYPE.C_IF:writer.write_if(parser.arg1()) elif parser.command_type() == C_TYPE.C_CALL:writer.write_call(parser.arg1(), parser.arg2()) elif parser.command_type() == C_TYPE.C_FUNCTION:writer.write_function(parser.arg1(), parser.arg2()) elif parser.command_type() == C_TYPE.C_RETURN:writer.write_return()# main programif os.path.isfile(sys.argv[1]) and sys.argv[1].endswith('.vm'): # 参数为 .vm 文件，只翻译一个文件 writer = CodeWriter(os.path.splitext(sys.argv[1])[0]+'.asm') writer.write_init() process_vm_file(sys.argv[1])elif os.path.isdir(sys.argv[1]): # 参数为文件夹，将文件夹中所有文件翻译为 hack 汇编 writer = CodeWriter(sys.argv[1]+'/'+os.path.basename(sys.argv[1])+'.asm') writer.write_init() for f in glob.glob(sys.argv[1] + '/*.vm'): process_vm_file(f)